Exemplary embodiments pertain to the art of motor vehicle starters and, more particularly, to an integrated magnetic switch assembly for a motor vehicle starter.
Vehicle starter motors are typically provided with a pinion gear and a solenoid. A shift lever operatively connects the solenoid to the drive assembly. The solenoid typically includes a solenoid coil that is linked to a solenoid plunger. The plunger is linked to the pinion gear though a shift lever. When the solenoid coil is energized, the solenoid plunger extends thereby pivoting the shift lever. The shift lever urges the pinion gear into operative engagement with a flywheel member provided in a vehicle engine.
Vehicle starters that utilize a soft-start engagement system supply a substantial amount of current prior to the solenoid coil prior to shifting the pinion gear into engagement with the flywheel and rotating the vehicle motor. Typically, current supplied to the solenoid ranges from 200 amps to 400 amps depending on the particular starter motor and engine. This amount of current is much greater than the 4-6 amps that common ignition switches are capable of reliably handling. Therefore, soft-start engagement systems usually employ a separate integrated magnetic switch (IMS).
The IMS limits current draw of the starter motor to typical levels, e.g., in the rage of 2-4 amps. When the IMS is activated, a pull-in coil in the solenoid is connected to a vehicle battery. Current then flows to the starter motor allowing the pinion gear to rotate and engage the flywheel. In certain systems an IMS is mounted directly to the solenoid and starter motor. Vehicle starter motors are exposed to a wide variety of contaminates. Motor oil, water, dust and other substances coat the vehicle starter during operation. Over time, some of the contaminants leech into the vehicle starter and IMS. The contaminants entering into the IMS interfere with electric contacts as well as limit movement of the pull-in coil.